Waterproof and moistureproof sheet and process of making same



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LESTER KIRSCHBBAUN, F CHICAGO; ILLINQIS.

WATERPROOF AND MOISTURWROOF SHEET `A 'LUD PROC 01E' MANG SAME.

' Application med August le, 1922..V Serial No. 582,305.

l0 This invention relates to the manufacture of waterproof and moistureroof sheets and l is more particularly directe to a product in which drysheets of paper are p sted together by means of a cold bitumino s cementin emulsion form. Y l

This bituminous cement may be formed .in accordance with the processdescribed in my prior Patent No. 1,417,835.

I have found that the following emulsion makes a very satisfactorycement.:

Ten parts offsteamdistilled Mexican asphalt of 120 to 130 vFahrenheitmelting point, one part of bentonite and ten parts of water, by Weight.vIt is desirable to use asvlittle of the emulsifying agent as feasible inorder to have a lmaximum stickiness in the dried cement.

In carrying out the invention I may take two sheets of dry paper andcement or paste them together by applying the emulsion to the opposedsurface of the sheets, uniting the sheets and passing themA throughpresser and drying rol s in such a way as to remove the Water and permitthe asphalt to coalesce. This forms a continuous waterproof andmoistureproof menstrum between the opposed plies of paper. 1

` it may not be necessaryv In some mstances to pass the sheets betweendrying rolls, particularly if heavy sheets are used, as the sheets maysimply dry Without the application of artificial heat. It is desirableto use an emulsifying agent such as bentonite for the reason that anemulsion formed with bentonite produces a smoothly flowing compositionin which the asphalt is easily suspended in finely dispersed form. It isto KmscHBRAUN,

be noted that this permits 'of-the use of a coldbituminous paste orcement. By the use of this cold emulsion any waste scrap collectedvprior to setting of the emulsion can be recovered by being maintained ina wet condition. j

I am mentioning the pasting together of ordinary sheets of paper. Theinvention is also applicable to the invention of corru-y gated sheets asfor example, strawboard and the like. 'Instead of using bentonite insome cases it maybe possible to use highgrade colloidal clay and insteadof Mexican asphalt of the character referred to, various kinds ofasphalts and vegetable or'mineral pitches may be used.

It is to be particularly noted that the L emulsion above referred toshould be of a relatively highly stable character so that it will notreadily break down during the spreading operation, i. e., when it isspread over the face of the sheets and thus tend to interfere with theoperation vof the machine. y I claim as my invention:

1. A process of making a Waterproof and i moistureproof sheet consistingin making an emulsion miscible in water and containing pitch and anemulsifying agent such'as bentonite and then applying said emulsionbetween opposed surfaces of fibrous sheets, y

removing t pitch to coalesce and forml a bituminous cement. 5'4

2. A process of making a" 'Waterproof and e water and permitting themoistureproof sheet consisting in making an emulsion miscible in `waterand containing pitch and an emulsifying agent and then applying saidemulsion between opposed surfaces of fibrous sheets, removing the waterand permitting the pitch to coalesce and form a bituminous cement.

3. A waterproof and moistureproof composite sheet consisting of opposedsheets and a bituminous cement containing an emulsifying agentinterposed therebetween.

LESTER KIRSCHBRAUN.

